Goatman

Goatman's real name is unknown, but it is implied that he was a human scientist. Due to an experiment gone wrong, he transformed into a chimera goat and human hybrid. His mind transformed into that of a savage and he is known to haunt nearby forests, plotting revenge on humanity by attacking those who enter his forest (especially pets, kids, and teenagers). He is violent and will attack anything that moves in front of him without a second thought or remorse. At some point, he encounters Zim, Dib, Gaz, GIR, and Tak when they are lost in his forest, but he was ultimatley defeated by Zim and Dib's unlikely alliance.